The present disclosure relates to a touch panel used for a screen input/display apparatus and the like, and a manufacturing method of the same.
A touch panel of an analog resistive type that detects input coordinates based on an amount of resistance change has been known (see, for example, Japanese Patent Application Laid-open No. 2002-215332). Japanese Patent Application Laid-open No. 2002-215332 discloses a touch panel including a fixed panel, a movable panel, and a double-sided tape for bonding the panels with a certain gap formed between the panels.
Inside of each of the fixed panel and the movable panel, an ITO conductive film is formed. On the conductive film, a pair of electrodes disposed so as to be opposed in a direction is formed for the fixed panel, and a pair of electrodes disposed so as to be opposed in a direction perpendicular to the above-mentioned direction is formed for the movable panel. The double-sided tape is located between the electrodes of each of the fixed panel and the movable panel, to electrically insulate the electrodes.
In the touch panel having the above structure, respective electrodes of the fixed side panel and the movable panel are covered with the double-sided tape. Meanwhile, the respective electrodes are each formed to have a predetermined thickness on the conductive film. Therefore, at a position of an end portion or a periphery portion of each electrode, a difference in level between a surface of the electrode and a surface of the conductive film is not absorbed due to adhesive surfaces of the double-sided tape, which causes gaps.
When the gaps have a predetermined size or more, a slight pressure difference generated between the inside and the outside of the touch panel causes the movable panel to sag inwards, which causes an interference fringe known as a Newton ring to easily occur. As a result, an appearance of the touch panel is impaired, or visibility of an image displayed through the touch panel becomes poor.
In view of the above-mentioned circumstances, it is desirable to provide a touch panel that is capable of suppressing the occurrence of the Newton ring due to the pressure difference.